Independent regulation of cytochromes and glycolytic enzymes in human fibroblasts

✍ Scribed by Donald A. Pious; Walter A. Susor; Robert W. Benson; William J. Rutter

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 454 KB
• Volume: 79
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040790312

✦ Synopsis

Growth of cultured human fibroblasts i n low oxygen resulted in reciprocal changes i n the levels of cytochrome oxidase and several glycolytic enzymes. After five days' growth in low oxygen, cytochrome oxidase specific activity fell to 40% of the level of control cultures, while lactic dehydrogenase (LDH), aldolase, and triose phosphate dehydrogenase (TDH) levels were increased by 2-to 3-fold. These changes were accompanied by a change in the LDH isoenzyme pattern resulting from an increase i n the proportion of LDH A subunits; the aldolase electropherogram was unchanged. When fibroblasts were grown for five days in medium containing chloramphenicol, cytochrome oxidase specific activity fell to 1 0 % of control values, but LDH, aldolase and TDH specific activities and LDH and aldolase electropherograms did not differ significantly from controls. These findings are interpreted to indicate that the increased accumulation of LDH, aldolase and TDH induced by low oxygen is not mediated by the rate of accumulation of cytochrome oxidase.